167 results on '"D. J. Hartley"'
Search Results
2. νi13/2 structures in Sm155 and Gd159 : Supporting evidence of a Z=60 deformed subshell gap
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D. J. Hartley, F. G. Kondev, M. P. Carpenter, R. V. F. Janssens, M. A. Riley, K. Villafana, K. Auranen, A. D. Ayangeakaa, J. S. Baron, A. J. Boston, J. A. Clark, J. P. Greene, J. Heery, C. R. Hoffman, T. Lauritsen, J. Li, D. Little, E. S. Paul, G. Savard, D. Seweryniak, J. Simpson, S. Stolze, G. L. Wilson, J. Wu, and S. Zhu
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- 2022
3. Two-phonon wobbling in 135Pr
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Q. B. Chen, N. Sensharma, A. D. Ayangeakaa, Y. K. Gupta, D. Seweryniak, J. L. Cozzi, J. Sethi, R. V. F. Janssens, F. G. Kondev, G. H. Bhat, S. S. Ghugre, D. J. Hartley, M. P. Carpenter, S. Zhu, J. A. Sheikh, R. P. Singh, S. Frauendorf, K. B. Howard, R. Palit, Wei Li, T. C. McMaken, and U. Garg
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Physics ,Nuclear and High Energy Physics ,Condensed matter physics ,010308 nuclear & particles physics ,Rotor (electric) ,Phonon ,Shell (structure) ,Conclusive evidence ,01 natural sciences ,lcsh:QC1-999 ,law.invention ,Transverse plane ,medicine.anatomical_structure ,Character (mathematics) ,law ,0103 physical sciences ,Quasiparticle ,medicine ,010306 general physics ,Nucleus ,lcsh:Physics - Abstract
The second-phonon ( n ω = 2 ) wobbling band has been established in the nucleus 135Pr. Conclusive evidence for its wobbling nature comes from the Δ I = 1 , E2 character of the transitions between the new band and the previously identified transverse wobbler band ( n ω = 1 ) in this nucleus. Theoretical calculations in the framework of the quasiparticle triaxial rotor and triaxial projected shell models are found to be in good agreement with the experimental results.
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- 2019
4. Possible quenching of static neutron pairing near the N=98 deformed shell gap: Rotational structures in Gd160,161
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Sanna Stolze, T. Lauritsen, John P. Greene, A. J. Boston, J. Li, G. L. Wilson, S. Zhu, J. Heery, Jayne Simpson, C. R. Hoffman, P. Jackson, F. G. Kondev, K. Villafana, Guy Savard, E. S. Paul, M. P. Carpenter, D. Little, S. Frauendorf, M. A. Riley, Kalle Auranen, Jin Wu, D. J. Hartley, R. V. F. Janssens, Jill S. Baron, Jason A. Clark, D. Seweryniak, and A. D. Ayangeakaa
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Quenching ,Physics ,Pairing ,Shell (structure) ,Neutron ,Molecular physics - Published
- 2021
5. Reply to: Possible overestimation of isomer depletion due to contamination
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J. Rzadkiewicz, John P. Greene, D. Seweryniak, Marek Polasik, M. P. Carpenter, A. B. Hayes, D. J. Hartley, S. Zhu, D. A. Matters, C. J. Chiara, J. J. Carroll, G. J. Lane, J. C. Marsh, R. V. F. Janssens, and S. Bottoni
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Multidisciplinary ,Chemistry ,Environmental chemistry ,Contamination - Published
- 2021
6. Spin-trap isomers in deformed, odd-odd nuclei in the light rare-earth region near N=98
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W. S. Porter, A. A. Valverde, X. L. Yan, D. J. Hartley, F. G. Kondev, R. Orford, M. T. Burkey, D. Ray, Jason A. Clark, K. S. Sharma, Guy Savard, Jeffrey Klimes, F. Buchinger, and D. A. Gorelov
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Physics ,Isotope ,010308 nuclear & particles physics ,Rare earth ,Canadian Penning Trap Mass Spectrometer ,chemistry.chemical_element ,Californium ,01 natural sciences ,chemistry ,0103 physical sciences ,Spin trap ,Atomic physics ,Nuclear Experiment ,010306 general physics - Abstract
Masses of neutron-rich, odd-odd Pm, Eu, and Tb nuclei near $N=98$ were measured using the Canadian Penning Trap mass spectrometer at the Californium Rare Isotope Breeder Upgrade (CARIBU) facility. High-resolution mass measurements yielded the discovery of spin-trap isomers at $N=97$ in $^{162}\mathrm{Tb}$, and in the $N=99$ isotones of $^{160}\mathrm{Pm}$ and $^{164}\mathrm{Tb}$. Furthermore, no evidence of long-lived isomers were observed at $N=95$ in $^{158}\mathrm{Eu}$, at $N=97$ in $^{158}\mathrm{Pm}$, nor at $N=101$ in $^{164}\mathrm{Eu}$ and $^{166}\mathrm{Tb}$. These experimental observations are compared to results from multiquasiparticle blocking calculations.
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- 2020
7. High- K , two-quasiparticle states in Gd160
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T. Lauritsen, P. Copp, R. Orford, S. Zhu, K. Hicks, Jason A. Clark, A. D. Ayangeakaa, F. G. Kondev, M. P. Carpenter, Guy Savard, Calem Hoffman, R. V. F. Janssens, S. Bottoni, J. Sethi, and D. J. Hartley
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Physics ,Decay scheme ,Excited state ,Quasiparticle ,State (functional analysis) ,Atomic physics ,High-κ dielectric - Abstract
Excited states in $^{160}\mathrm{Gd}$ were populated via $\ensuremath{\beta}$ decay from the low- and high-spin isomers in $^{160}\mathrm{Eu}$. The high-spin, ${K}^{\ensuremath{\pi}}={5}^{\ensuremath{-}}$ state feeds several two-quasiparticle levels, as well as a sequence associated with a $\ensuremath{\gamma}$ vibration and a ${K}^{\ensuremath{\pi}}={4}^{+}$, hexadecapole vibrational structure. The decay scheme was significantly improved with the observation of new transitions and states when compared with the two competing level schemes from over four decades ago. Configuration assignments for some of the multiquasiparticle levels have been suggested, based upon decay properties, systematics from neighboring nuclei, and comparisons with theoretical calculations. In addition, 15 new low-spin states and approximately 60 new transitions were observed resulting from the decay of the low-spin $^{160}\mathrm{Eu}$ isomer.
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- 2020
8. Nuclear Data Sheets for A=188
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F. G. Kondev, D. J. Hartley, and Sakari Juutinen
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Mass number ,Physics ,Nuclear and High Energy Physics ,ta114 ,010308 nuclear & particles physics ,evaluated nuclear structure ,Nuclear structure ,Nuclear data ,Experimental data ,Quantum number ,01 natural sciences ,Nuclear physics ,0103 physical sciences ,010306 general physics - Abstract
Evaluated nuclear structure and decay data for all nuclei with mass number A=188 (Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po) are presented. The experimental data are compiled and evaluated, and best values for level and gamma-ray energies, quantum numbers, lifetimes, gamma-ray intensities, and other nuclear properties are recommended. Inconsistencies and discrepancies that exist in the literature are noted. This work supersedes the earlier evaluation by Balraj Singh (2002Si10), published in Nuclear Data Sheets 95, 387 (2002). The gamma-ray transition probabilities were calculated using the ENSDF analysis program ruler ( www-nds.iaea.org/public/ensdf_pgm/ ). However, the reader should be warned that the program may produce incorrect results when dealing with non-symmetric uncertainties.
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- 2018
9. Corrigendum to 'Two-phonon wobbling in 135Pr' [Phys. Lett. B 792 (2019) 170–174]
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Y. K. Gupta, Q. B. Chen, D. Seweryniak, Wei Li, U. Garg, M. P. Carpenter, R. V. F. Janssens, R. Palit, J. Sethi, T. C. McMaken, S. Frauendorf, G. H. Bhat, N. Sensharma, D. J. Hartley, J. A. Sheikh, F. G. Kondev, K. B. Howard, R. P. Singh, J. L. Cozzi, A. D. Ayangeakaa, S. S. Ghugre, and S. Zhu
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Physics ,Nuclear and High Energy Physics ,Condensed matter physics ,Phonon ,QC1-999 - Published
- 2021
10. Isomer depletion as experimental evidence of nuclear excitation by electron capture
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J. Rzadkiewicz, S. Zhu, D. Seweryniak, Gregory Lane, John P. Greene, S. A. Karamian, D. A. Matters, Marek Polasik, James Carroll, M. P. Carpenter, S. Bottoni, Robert V. F. Janssens, C. J. Chiara, D. J. Hartley, J. C. Marsh, and A. B. Hayes
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Physics ,Multidisciplinary ,Isotope ,010308 nuclear & particles physics ,Electron capture ,Binding energy ,Electron ,Kinetic energy ,01 natural sciences ,Internal conversion ,Excited state ,0103 physical sciences ,Atomic nucleus ,Atomic physics ,010306 general physics - Abstract
The atomic nucleus and its electrons are often thought of as independent systems that are held together in the atom by their mutual attraction. Their interaction, however, leads to other important effects, such as providing an additional decay mode for excited nuclear states, whereby the nucleus releases energy by ejecting an atomic electron instead of by emitting a γ-ray. This 'internal conversion' has been known for about a hundred years and can be used to study nuclei and their interaction with their electrons. In the inverse process-nuclear excitation by electron capture (NEEC)-a free electron is captured into an atomic vacancy and can excite the nucleus to a higher-energy state, provided that the kinetic energy of the free electron plus the magnitude of its binding energy once captured matches the nuclear energy difference between the two states. NEEC was predicted in 1976 and has not hitherto been observed. Here we report evidence of NEEC in molybdenum-93 and determine the probability and cross-section for the process in a beam-based experimental scenario. Our results provide a standard for the assessment of theoretical models relevant to NEEC, which predict cross-sections that span many orders of magnitude. The greatest practical effect of the NEEC process may be on the survival of nuclei in stellar environments, in which it could excite isomers (that is, long-lived nuclear states) to shorter-lived states. Such excitations may reduce the abundance of the isotope after its production. This is an example of 'isomer depletion', which has been investigated previously through other reactions, but is used here to obtain evidence for NEEC.
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- 2018
11. Fast-timing measurements in the ground-state band of Pd114
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T. Lauritsen, T. Kröll, L. A. Gurgi, F. G. Kondev, G. J. Lane, I. Burrows, D. M. Cullen, O. Yordanov, S. Lalkovski, Alison Bruce, John P. Greene, T. Daniel, V. F. E. Pucknell, D. Seweryniak, D. J. Hartley, Gavin Lotay, C. M. Shand, M. Smolen, T. Berry, S. Bottoni, C. R. Niţă, E. A. Stefanova, J. Sethi, E.R. Gamba, R. Ilieva, M. Carmona Gallardo, S. Zhu, J. Rohrer, J. T. Anderson, A. D. Ayangeakaa, S. Ilieva, J. Simpson, Matthew Reed, M. P. Carpenter, P. Copp, M. Rudigier, V. Vedia, I.H. Lazarus, P. H. Regan, Raymond J. Carroll, Zs. Podolyák, and G. Fernández Martínez
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Physics ,Work (thermodynamics) ,Isotope ,Yrast ,chemistry.chemical_element ,medicine.anatomical_structure ,chemistry ,medicine ,Gammasphere ,Interacting boson model ,Atomic physics ,Ground state ,Nucleus ,Palladium - Abstract
Using a hybrid Gammasphere array coupled to 25 LaBr3(Ce) detectors, the lifetimes of the first three levels of the yrast band in ¹¹⁴Pd populated via ²⁵²Cf decay, have been measured. The measured lifetimes are τ₂+=103(10)ps, τ₄+=22(13)ps, and τ₆+≤10ps for the 2⁺₁, 4⁺₁, and 6⁺₁ levels, respectively. Palladium-114 was predicted to be the most deformed isotope of its isotopic chain, and spectroscopic studies have suggested it might also be a candidate nucleus for low-spin stable triaxiality. From the lifetimes measured in this work, reduced transition probabilities B(E2;J→J−2) are calculated and compared with interacting boson model, projected shell model, and collective model calculations from the literature. The experimental ratio RB(E₂)=B(E2;4⁺₁→2⁺₁)/B(E2;2⁺₁→0⁺₁)=0.80(42) is measured for the first time in ¹¹⁴Pd and compared with the known values RB(E₂) in the palladium isotopic chain: the systematics suggest that, for N=68, a transition from γ-unstable to a more rigid γ-deformed nuclear shape occurs.
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- 2019
12. Spectroscopy of low-spin states in Dy157 : Search for evidence of enhanced octupole correlations
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L. Bianco, Robert Bark, B. M. Nyakó, T. D. Bucher, P. L. Masiteng, J. Ndayishimye, Steffen Ketelhut, E. A. Lawrie, G. Zimba, L. Mdletshe, O. Shirinda, Peter B. Jones, C. Scholey, S. S. Ntshangase, D. M. Cullen, R. T. Newman, Pauli Peura, D. J. Hartley, S. N. T. Majola, J.F. Sharpey-Schafer, A. Minkova, S. P. Bvumbi, B. V. Kheswa, B. Maqabuka, Ulrika Jakobsson, Juha Sorri, Juha Uusitalo, P. Ruotsalainen, S. Juutinen, J. Hirvonen, M. A. Riley, Sanna Stolze, József Tímár, P. Rahkila, D. G. Roux, P. E. Garrett, A. Sithole, Paivi Nieminen, R. Julin, L. L. Riedinger, Jan Sarén, A. Korichi, and Paul Greenlees
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Physics ,Nuclear physics ,Spin states ,010308 nuclear & particles physics ,0103 physical sciences ,Nuclear structure ,010306 general physics ,Spectroscopy ,01 natural sciences ,Nuclear theory ,3. Good health - Abstract
CITATION: Majola, S. N. T., et al. 2019. Spectroscopy of low-spin states in 157Dy : Search for evidence of enhanced octupole correlations. Physical Review C, 100(6):034322, doi:10.1103/PhysRevC.100.034322.
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- 2019
13. Evidence for Rigid Triaxial Deformation in Ge76 from a Model-Independent Analysis
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R. V. F. Janssens, H. L. Crawford, Alexandra Gade, D. Cline, D. Rhodes, D. J. Hartley, S. Stolze, M. Albers, A. D. Ayangeakaa, P. Fallon, M. P. Carpenter, W. B. Walters, D. Seweryniak, Krishichayan, Ching-Yen Wu, D. Little, P. Chowdhury, A. B. Hayes, A. M. Forney, A. O. Macchiavelli, Kalle Auranen, Jin Wu, J. Li, Jack Henderson, Brian Bucher, T. Lauritsen, F. G. Kondev, and S. Zhu
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Physics ,Basis (linear algebra) ,media_common.quotation_subject ,General Physics and Astronomy ,Coulomb excitation ,Deformation (meteorology) ,Statistical fluctuations ,16. Peace & justice ,01 natural sciences ,Asymmetry ,Molecular physics ,Matrix (mathematics) ,0103 physical sciences ,Quadrupole ,010306 general physics ,Nuclear theory ,media_common - Abstract
An extensive, model-independent analysis of the nature of triaxial deformation in ^{76}Ge, a candidate for neutrinoless double-beta (0νββ) decay, was carried out following multistep Coulomb excitation. Shape parameters deduced on the basis of a rotational-invariant sum-rule analysis provided considerable insight into the underlying collectivity of the ground-state and γ bands. Both sequences were determined to be characterized by the same β and γ deformation parameter values. In addition, compelling evidence for low-spin, rigid triaxial deformation in ^{76}Ge was obtained for the first time from the analysis of the statistical fluctuations of the quadrupole asymmetry deduced from the measured E2 matrix elements. These newly determined shape parameters are important input and constraints for calculations aimed at providing, with suitable accuracy, the nuclear matrix elements relevant to 0νββ.
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- 2019
14. Backbending, seniority, and Pauli blocking of pairing correlations at high rotational frequencies in rapidly rotating nuclei
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S. Zhu, E. A. McCutchan, M. P. Carpenter, P. F. Bertone, T. Lauritsen, Alexander Volya, J. Cavey, P. Chowdhury, J. T. Matta, J.F. Sharpey-Schafer, E.G. Jackson, K. Villafana, J. J. Carroll, F. G. Kondev, C. J. Chiara, S. S. Hota, A. D. Ayangeakaa, A. J. Boston, D. J. Hartley, Jayne Simpson, Xuan Wang, Saul L. Miller, S. Mukhopadhyay, R. V. F. Janssens, E. S. Paul, M. A. Riley, Jill S. Baron, U. Garg, Marc Litz, W. C. Ma, J. R. Vanhoy, P. J. Nolan, E. E. Pedicini, and L. L. Riedinger
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Physics ,symbols.namesake ,Pauli exclusion principle ,Blocking (radio) ,Quantum mechanics ,Pairing ,symbols ,Seniority - Abstract
Garrett et al. systematically investigated band-crossing frequencies resulting from the rotational alignment of the first pair of i13/2 neutrons (AB) in rare-earth nuclei. In that study, evidence was found for an odd-even neutron number dependence attributed to changes in the strength of neutron pairing correlations. The present paper carries out a similar investigation at higher rotational frequencies for the second pair of aligning i13/2 neutrons (BC). Again, a systematic difference in band-crossing frequencies is observed between odd-N and even-N Er, Yb, Hf, and W nuclei, but in the BC case, it is opposite to the AB neutron-number dependence. These results are discussed in terms of a reduction of neutron pairing correlations at high rotational frequencies and of the effects of Pauli blocking on the pairing field by higher-seniority configurations. Also playing a significant role are the changes in deformation with proton and neutron numbers, the changes in location of single-particle orbitals as a function of quadrupole deformation, and the position of the Fermi surface with regard to the various ω components of the neutron i13/2 shell.
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- 2019
15. Evidence for rigid triaxial deformation in $^{76}$Ge from a model-independent analysis
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A D, Ayangeakaa, R V F, Janssens, S, Zhu, D, Little, J, Henderson, C Y, Wu, D J, Hartley, M, Albers, K, Auranen, B, Bucher, M P, Carpenter, P, Chowdhury, D, Cline, H L, Crawford, P, Fallon, A M, Forney, A, Gade, A B, Hayes, F G, Kondev, Krishichayan, T, Lauritsen, J, Li, A O, Macchiavelli, D, Rhodes, D, Seweryniak, S M, Stolze, W B, Walters, and J, Wu
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Nuclear Theory (nucl-th) ,Nuclear Theory ,FOS: Physical sciences ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment - Abstract
An extensive, model-independent analysis of the nature of triaxial deformation in $^{76}$Ge, a candidate for neutrinoless double-beta ($0\nu\beta\beta$) decay, was carried out following multi-step Coulomb excitation. Shape parameters deduced on the basis of a rotational-invariant sum-rule analysis provided considerable insight into the underlying collectivity of the ground-state and $\gamma$ bands. Both sequences were determined to be characterized by the same $\beta$ and $\gamma$ deformation parameter values. In addition, compelling evidence for low-spin, rigid triaxial deformation in $^{76}$Ge was obtained for the first time from the analysis of the statistical fluctuations of the quadrupole asymmetry deduced from the measured $E2$ matrix elements. These newly determined shape parameters are important input and constraints for calculations aimed at providing, with suitable accuracy, the nuclear matrix elements relevant to $0\nu\beta\beta$., Comment: 6 pages, 5 figures
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- 2019
- Full Text
- View/download PDF
16. Masses and β -Decay Spectroscopy of Neutron-Rich Odd-Odd Eu160,162 Nuclei: Evidence for a Subshell Gap with Large Deformation at N=98
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F. G. Kondev, S. Bottoni, D. J. Hartley, S. Zhu, Guy Savard, P. Copp, T. Lauritsen, M. T. Burkey, K. Hicks, Jason A. Clark, R. Orford, D. A. Gorelov, M. P. Carpenter, R. V. F. Janssens, D. Seweryniak, K. S. Sharma, Jeffrey Klimes, Calem Hoffman, C. Hu, Haifei Zhang, J. Sethi, F. Buchinger, A. D. Ayangeakaa, and Yu Jiao Zhu
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Physics ,Large deformation ,Isotope ,010308 nuclear & particles physics ,Nuclear Theory ,Nuclear structure ,General Physics and Astronomy ,chemistry.chemical_element ,Californium ,01 natural sciences ,Nuclear physics ,chemistry ,Neutron number ,0103 physical sciences ,Neutron ,Nuclear Experiment ,010306 general physics ,National laboratory ,Spectroscopy - Abstract
The structure of deformed neutron-rich nuclei in the rare-earth region is of significant interest for both the astrophysics and nuclear structure fields. At present, a complete explanation for the observed peak in the elemental abundances at $A\ensuremath{\sim}160$ eludes astrophysicists, and models depend on accurate quantities, such as masses, lifetimes, and branching ratios of deformed neutron-rich nuclei in this region. Unusual nuclear structure effects are also observed, such as the unexpectedly low energies of the first ${2}^{+}$ levels in some even-even nuclei at $N=98$. In order to address these issues, mass and $\ensuremath{\beta}$-decay spectroscopy measurements of the $^{160}{\mathrm{Eu}}_{97}$ and $^{162}{\mathrm{Eu}}_{99}$ nuclei were performed at the Californium Rare Isotope Breeder Upgrade radioactive beam facility at Argonne National Laboratory. Evidence for a gap in the single-particle neutron energies at $N=98$ and for large deformation (${\ensuremath{\beta}}_{2}\ensuremath{\sim}0.3$) is discussed in relation to the unusual phenomena observed at this neutron number.
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- 2018
17. Masses and β-Decay Spectroscopy of Neutron-Rich Odd-Odd ^{160,162}Eu Nuclei: Evidence for a Subshell Gap with Large Deformation at N=98
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D J, Hartley, F G, Kondev, R, Orford, J A, Clark, G, Savard, A D, Ayangeakaa, S, Bottoni, F, Buchinger, M T, Burkey, M P, Carpenter, P, Copp, D A, Gorelov, K, Hicks, C R, Hoffman, C, Hu, R V F, Janssens, J W, Klimes, T, Lauritsen, J, Sethi, D, Seweryniak, K S, Sharma, H, Zhang, S, Zhu, and Y, Zhu
- Abstract
The structure of deformed neutron-rich nuclei in the rare-earth region is of significant interest for both the astrophysics and nuclear structure fields. At present, a complete explanation for the observed peak in the elemental abundances at A∼160 eludes astrophysicists, and models depend on accurate quantities, such as masses, lifetimes, and branching ratios of deformed neutron-rich nuclei in this region. Unusual nuclear structure effects are also observed, such as the unexpectedly low energies of the first 2^{+} levels in some even-even nuclei at N=98. In order to address these issues, mass and β-decay spectroscopy measurements of the ^{160}Eu_{97} and ^{162}Eu_{99} nuclei were performed at the Californium Rare Isotope Breeder Upgrade radioactive beam facility at Argonne National Laboratory. Evidence for a gap in the single-particle neutron energies at N=98 and for large deformation (β_{2}∼0.3) is discussed in relation to the unusual phenomena observed at this neutron number.
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- 2018
18. N=151Pu,Cm and Cf nuclei under rotational stress: Role of higher-order deformations
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N. D'Olympia, S. Zhu, D. Peterson, Y. Qiu, R. V. F. Janssens, S. Lakshmi, D. Seweryniak, T. Harrington, C.J. Guess, M. P. Carpenter, C. J. Lister, U. Shirwadkar, P. Chowdhury, Calem Hoffman, I. Ahmad, P. F. Bertone, T. Lauritsen, S. Gros, I. Stefanescu, E.G. Jackson, A. Y. Deo, D. J. Hartley, T. L. Khoo, S. S. Hota, F. G. Kondev, S. K. Tandel, Cherupally Krishnan Krishnan Nair, E. A. McCutchan, C. J. Chiara, K. Moran, G. Henning, and John P. Greene
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Stress (mechanics) ,Physics ,Nuclear and High Energy Physics ,010308 nuclear & particles physics ,Isotone ,Excited state ,0103 physical sciences ,Order (group theory) ,Atomic physics ,010306 general physics ,01 natural sciences ,Excitation - Abstract
Fast-rotating N = 151 isotones 245 Pu, 247 Cm and 249 Cf have been studied through inelastic excitation and transfer reactions with radioactive targets. While all have a ground-state band built on a ν j 15 / 2 [ 734 ] 9 / 2 − Nilsson configuration, new excited bands have also been observed in each isotone. These odd- N excited bands allow a comparison of the alignment behavior for two different configurations, where the ν j 15 / 2 alignment is either blocked or allowed. The effect of higher order deformations is explored through cranking calculations, which help clarify the elusive nature of ν j 15 / 2 alignments.
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- 2014
19. Investigation of negative-parity states in Dy156 : Search for evidence of tetrahedral symmetry
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M. A. Riley, Scott L. Miller, E. A. McCutchan, W. D. Kulp, J. L. Wood, T. Lauritsen, S. Zhu, R. V. F. Janssens, J. M. Allmond, C.-H. Yu, J. Piot, D.W. Miller, Xuan Wang, I. Stefanescu, F. G. Kondev, N. Cooper, S. N. T. Majola, B. J. P. Gall, L. L. Riedinger, J.F. Sharpey-Schafer, P. E. Garrett, J. Dudek, C. J. Chiara, D. Curien, D. J. Hartley, C. W. Beausang, M. P. Carpenter, J. Simpson, V. Werner, and N. Redon
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Physics ,Rare earth nuclei ,Light nucleus ,Particle physics ,010308 nuclear & particles physics ,Hadron ,Nuclear structure ,Parity (physics) ,Elementary particle ,Tetrahedral symmetry ,01 natural sciences ,Baryon ,Quantum mechanics ,0103 physical sciences ,010306 general physics - Published
- 2017
20. Fast timing measurement using an labr3(Ce) scintillator detector array coupled with gammasphere
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Alec Grant, T. Kröll, V. F. E. Pucknell, I. Burrows, J. T. Anderson, G. Fernández Martínez, S. Bottoni, T. Daniel, F. G. Kondev, R. Ilieva, S. Zhu, V. Vedia, A. D. Ayangeakaa, E. A. Stefanova, T. Lauritsen, D. Seweryniak, Gavin Lotay, M. Rudigier, John P. Greene, I.H. Lazarus, S. Lalkovski, E.R. Gamba, P. H. Regan, R. V. F. Janssens, M. Smolen, C. M. Shand, D. J. Hartley, J. Sethi, M. P. Carpenter, Gregory Lane, D. M. Cullen, L.A. Guegi, T. Berry, P. Copp, J. Rohrer, Raymond J. Carroll, O. Yordanov, M. Carmona Gallardo, Jayne Simpson, Alison Bruce, Zs. Podolyák, Matthew Reed, S. Ilieva, and L. M. Fraile
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Physics ,Fission products ,010308 nuclear & particles physics ,Fission ,General Physics and Astronomy ,Radiation ,Nanosecond ,Scintillator ,01 natural sciences ,Nuclear physics ,Data acquisition ,Picosecond ,0103 physical sciences ,Gammasphere ,Física nuclear ,010306 general physics - Abstract
A fast-timing experiment was performed at the Argonne National Laboratory in December 2015 and January 2016, measuring decay radiation of fission products from a Cf-252 fission source. Details of the set-up, integration with Digital Gammasphere, and the data acquisition system are presented. The timing performance of the set-up, capable of measuring lifetimes from the nanosecond region down to tens of picoseconds, is discussed. First preliminary results from the fast-timing analysis of the fission fragment data are presented.
- Published
- 2017
- Full Text
- View/download PDF
21. In-beam γ -ray spectroscopy of S38–42
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E. Lunderberg, S. R. Stroberg, D. J. Hartley, F. Recchia, Kathrin Wimmer, B. A. Brown, J. S. Berryman, Daniel Bazin, T.R. Baugher, V. M. Bader, D. Weisshaar, and Alexandra Gade
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Physics ,education.field_of_study ,010308 nuclear & particles physics ,Yrast ,Nuclear Theory ,Population ,01 natural sciences ,symbols.namesake ,Excited state ,0103 physical sciences ,symbols ,Atomic physics ,Nuclear Experiment ,010306 general physics ,Spectroscopy ,education ,Hamiltonian (quantum mechanics) ,Projectile fragmentation ,Excitation - Abstract
The low-energy excitation level schemes of the neutron-rich $^{38--42}\mathrm{S}$ isotopes are investigated via in-beam $\ensuremath{\gamma}$-ray spectroscopy following the fragmentation of $^{48}\mathrm{Ca}$ and $^{46}\mathrm{Ar}$ projectiles on a $^{12}\mathrm{C}$ target at intermediate beam energies. Information on $\ensuremath{\gamma}\ensuremath{\gamma}$ coincidences complemented by comparisons to shell-model calculations were used to construct level schemes for these neutron-rich nuclei. The experimental data are discussed in the context of large-scale shell-model calculations with the SDPF-MU effective interaction in the $sd\text{\ensuremath{-}}pf$ shell. For the even-mass S isotopes, the evolution of the yrast sequence is explored as well as a peculiar change in decay pattern of the second ${2}^{+}$ states at $N=26$. For the odd-mass $^{41}\mathrm{S}$, a level scheme is presented that seems complete below 2.2 MeV and consistent with the predictions by the SDPF-MU shell-model Hamiltonian; this is a remarkable benchmark given the rapid shell and shape evolution at play in the S isotopes as the broken-down $N=28$ magic number is approached. Furthermore, the population of excited final states in projectile fragmentation is discussed.
- Published
- 2016
22. First observation of rotational structures in Re168
- Author
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E. A. McCutchan, P. Chowdhury, T. Lauritsen, S. S. Hota, E. E. Pedicini, D. J. Hartley, C. J. Chiara, F. G. Kondev, J. T. Matta, J. R. Vanhoy, R. V. F. Janssens, U. Garg, Saul L. Miller, S. Zhu, S. Mukhopadhyay, M. A. Riley, W. C. Ma, L. L. Riedinger, M. P. Carpenter, P. F. Bertone, Xuan Wang, G. Gürdal, and A. D. Ayangeakaa
- Subjects
Physics ,Spins ,chemistry ,010308 nuclear & particles physics ,0103 physical sciences ,chemistry.chemical_element ,Multiplicity (chemistry) ,Atomic physics ,Rhenium ,010306 general physics ,01 natural sciences ,Energy (signal processing) ,Spin-½ - Abstract
The first rotational sequences have been assigned to the odd-odd nucleus $^{168}\mathrm{Re}$. Coincidence relationships of these structures with rhenium x rays confirm the isotopic assignment, while arguments based on the $\ensuremath{\gamma}$-ray multiplicity ($K$-fold) distributions observed with the new bands lead to the mass assignment. Configurations for the two bands were determined through analysis of the rotational alignments of the structures and a comparison of the experimental $B(M1)/B(E2)$ ratios with theory. Tentative spin assignments are proposed for the $\ensuremath{\pi}{h}_{11/2}\ensuremath{\nu}{i}_{13/2}$ band, based on energy level systematics for other known sequences in neighboring odd-odd rhenium nuclei, as well as on systematics seen for the signature inversion feature that is well known in this region. The spin assignment for the $\ensuremath{\pi}{h}_{11/2}\ensuremath{\nu}({h}_{9/2}/{f}_{7/2})$ structure provides additional validation of the proposed spins and configurations for isomers in the $^{176}\mathrm{Au} \ensuremath{\rightarrow} ^{172}\mathrm{Ir}\ensuremath{\rightarrow}^{168}\mathrm{Re} \ensuremath{\alpha}$-decay chain.
- Published
- 2016
23. Masses and Beta-decay Studies of Neutron-rich Nuclei using the X-array and Gammasphere
- Author
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D. Seweryniak, S. Bottoni, S. T. Marley, K. Hicks, T. Lauritsen, S. Stolze, T. Li, F. G. Kondev, G.E. Morgan, G. Mukherjee, Jin Wu, Jason A. Clark, D. J. Hartley, Kalle Auranen, R. Orford, S. Zhu, R. B. Yadav, P. Copp, A. D. Ayangeakaa, R. V. F. Janssens, M. P. Carpenter, B. P. Kay, S. Nandi, Calem Hoffman, W. Reviol, Jasmine Sethi, and Guy Savard
- Subjects
Physics ,Isotope ,QC1-999 ,Nuclear Theory ,Nuclear structure ,chemistry.chemical_element ,Californium ,Penning trap ,Nuclear physics ,chemistry ,Excited state ,r-process ,Gammasphere ,Neutron ,Nuclear Experiment - Abstract
Properties of neutron-rich nuclei in the A˜160 region are important for achieving a better understanding of the nuclear structure in this region where little is known owing to diffculties in the production of these nuclei at the present nuclear physics facilities. These properties are essential ingredients in the interpretation of the rareearth peak at A˜160 in the r process abundance distribution, since theoretical models are sensitive to nuclear structure input. Predicated on these ideas, we have initiated a new experimental program at Argonne National Laboratory. During the first experiment, beams from the Californium Rare Isotope Breeder Upgrade radioactive beam facility were used in conjunction with the SATURN decay station and the X-array. We focused initially on several odd-odd nuclei, where β decays of both the ground state and an excited isomer were investigated. Because of the spin difference, a variety of structures in the daughter nuclei were selectively populated and characterized based on their decay properties. Mass measurements using the Canadian Penning Trap aimed at establishing the excitation energy of the β-decaying isomers were also carried out. Evidence was found for a change in the single-particle structure, which in turn results in the formation of a sizable N=98 sub-shell gap at large deformation. Results from the first experimental campaign using the newly-commissioned β-decay station at Gammasphere are also presented.
- Published
- 2019
24. Single-particle structure atN=29: The structure ofAr47and first spectroscopy ofS45
- Author
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J. S. Berryman, E. Lunderberg, B. A. Brown, F. Recchia, Daniel Bazin, D. Weisshaar, D. J. Hartley, S. R. Stroberg, C. Aa. Diget, T.R. Baugher, V. M. Bader, Kathrin Wimmer, T. Glasmacher, J. A. Tostevin, A. Ratkiewicz, and Alexandra Gade
- Subjects
Physics ,010308 nuclear & particles physics ,Structure (category theory) ,01 natural sciences ,medicine.anatomical_structure ,0103 physical sciences ,medicine ,Particle ,Direct reaction ,Atomic physics ,010306 general physics ,Ground state ,Spectroscopy ,Nucleus - Abstract
Comprehensive spectroscopy of the N = 29 nucleus 47Ar is presented, based on two complemen-tary direct reaction mechanisms: one-neutron pickup onto 46Ar projectiles and one-proton removal from the 1− ground state of 48K. The results are compared to shell-model calculations that use the state-of-the-art SDPF-U and SDPF-MU effective interactions. Also, from the 9Be(46Cl,45S+γ)X one-proton removal reaction, we report the first γ-ray transitions observed from 45S. Using compar-isons with shell-model calculations, and from the observed intensities and energy sums, we propose a first tentative level scheme for 45S.
- Published
- 2016
25. One-neutron pickup intoCa49: Bound neutrong9/2spectroscopic strength atN=29
- Author
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Kathrin Wimmer, D. J. Hartley, B. A. Brown, V. M. Bader, J. S. Berryman, Alexandra Gade, D. Weisshaar, S. R. Stroberg, J. A. Tostevin, F. Recchia, T.R. Baugher, D. Bazin, E. Lunderberg, and Yutaka Utsuno
- Subjects
Physics ,010308 nuclear & particles physics ,Projectile ,Nuclear Theory ,Ab initio ,Shell (structure) ,Inelastic scattering ,Quantum number ,01 natural sciences ,Atomic orbital ,0103 physical sciences ,Neutron ,Atomic physics ,Nuclear Experiment ,010306 general physics ,Spectroscopy - Abstract
The highly selective, intermediate-energy heavy-ion-induced neutron-pickup reaction, in combination with γ-ray spectroscopy using the γ-ray energy-tracking in-beam nuclear array (GRETINA), is shown to provide reliable relative spectroscopic strengths for high-l orbitals in nuclei more neutron rich than the projectile. The reaction mechanism gives a significant final-state-spin alignment that is validated through γ-ray angular-distribution measurements enabled by the position sensitivity of GRETINA. This is the first time that γ-ray angular distributions could be extracted from a high-luminosity, fast-beam reaction other than inelastic scattering. This holds great promise for the restriction and assignment of Jπ quantum numbers in exotic nuclei. We advance this approach to study the crucial N=28 shell closure and extract the ratio g9/2:f5/2 of bound neutron single-particle strengths in Ca49, a benchmark for emerging multi-shell ab initio and configuration-interaction theories that are applicable along the Ca isotopic chain.
- Published
- 2016
26. Quadrupole moments of collective structures up to spin ∼65ℏ in 157Er and 158Er: A challenge for understanding triaxiality in nuclei
- Author
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C. Unsworth, S. Zhu, J. Simpson, L. L. Riedinger, P. J. Nolan, T. Lauritsen, M. A. Riley, F. G. Kondev, Martin Carpenter, H. C. Boston, J. T. Matta, J. P. Revill, R. V. F. Janssens, N. M. Lumley, C. J. Chiara, E. S. Paul, J. Ollier, D. S. Judson, Ingemar Ragnarsson, U. Garg, Susan Rigby, A. D. Ayangeakaa, Xuan Wang, D. J. Hartley, and Marina Petri
- Subjects
Physics ,Nuclear and High Energy Physics ,Short axis ,010308 nuclear & particles physics ,Nuclear Theory ,Rotation ,01 natural sciences ,0103 physical sciences ,Quadrupole ,Atomic physics ,Deformation (engineering) ,010306 general physics ,Spin (physics) ,Principal axis theorem ,Bar (unit) - Abstract
The transition quadrupole moments. Q(t), of four weakly populated collective bands up to spin similar to 65h in Er-157,Er-158 have been measured to be similar to II eb demonstrating that these sequences are associated with large deformations. However, the data are inconsistent with calculated values from cranked Nilsson-Strutinsky calculations that predict the lowest energy triaxial shape to be associated with rotation about the short principal axis. The data appear to favor either a stable triaxial shape rotating about the intermediate axis or, alternatively, a triaxial shape with larger deformation rotating about the short axis. These new results challenge the present understanding of triaxiality in nuclei. (C) 2011 Elsevier B.V. All rights reserved. (Less)
- Published
- 2011
27. Publisher’s Note: Decay and Fission Hindrance of Two- and Four-QuasiparticleKIsomers inRf254[Phys. Rev. Lett.115, 132502 (2015)]
- Author
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D. T. Doherty, Nicholas Esker, John P. Greene, Sanna Stolze, B. B. Back, S. Zhu, B. Baartman, Juho Rissanen, J. T. Kwarsick, M. P. Carpenter, Jun Chen, D. Seweryniak, J. M. Gates, R. M. Clark, C. R. Hoffman, P. Ruotsalainen, D. J. Hartley, T. Lauritsen, R. V. F. Janssens, C. Nair, P. F. Bertone, C. J. Chiara, Guy Savard, F. G. Kondev, M. Cromaz, T. L. Khoo, S. S. Hota, Oliver Gothe, Paul Greenlees, Y. Qiu, H. M. David, Andreas Wiens, M. Alcorta, Iftikhar Ahmad, A. M. Rogers, C. M. Campbell, G.D. Dracoulis, K. Hauschild, P. Fallon, P. R. Mudder, K. E. Gregorich, A. O. Macchiavelli, M. Albers, L. A. Bernstein, and J. Konki
- Subjects
Physics ,Superconducting cyclotron ,Fission ,Quasiparticle ,General Physics and Astronomy ,Mathematical physics - Abstract
week ending 16 OCTOBER 2015 PHYSICAL REVIEW LETTERS PRL 115, 169902 (2015) Publisher’s Note: Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in 254 Rf [Phys. Rev. Lett. 115, 132502 (2015)] H. M. David, J. Chen, D. Seweryniak, F. G. Kondev, J. M. Gates, K. E. Gregorich, I. Ahmad, M. Albers, M. Alcorta, B. B. Back, B. Baartman, P. F. Bertone, L. A. Bernstein, C. M. Campbell, M. P. Carpenter, C. J. Chiara, R. M. Clark, M. Cromaz, D. T. Doherty, G. D. Dracoulis, N. E. Esker, P. Fallon, O. R. Gothe, J. P. Greene, P. T. Greenlees, D. J. Hartley, K. Hauschild, C. R. Hoffman, S. S. Hota, R. V. F. Janssens, T. L. Khoo, J. Konki, J. T. Kwarsick, T. Lauritsen, A. O. Macchiavelli, P. R. Mudder, C. Nair, Y. Qiu, J. Rissanen, A. M. Rogers, P. Ruotsalainen, G. Savard, S. Stolze, A. Wiens, and S. Zhu (Received 7 October 2015; published 16 October 2015) DOI: 10.1103/PhysRevLett.115.169902 PACS numbers: 23.20.Lv, 21.10.Tg, 23.35.+g, 27.90.+b, 99.10.Fg This paper was published online on 24 September 2015 with a tagging error resulting in an incorrect author footnote. J. Chen’s footnote should read as “ ‡ Present address: National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.” The paper has been corrected as of 29 September 2015. The footnote is correct in the printed version of the journal. © 2015 American Physical Society
- Published
- 2015
28. Decay and Fission Hindrance of Two- and Four-QuasiparticleKIsomers inRf254
- Author
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A. O. Macchiavelli, K. Hauschild, P. R. Mudder, P. Fallon, C. Nair, George Dracoulis, O.R. Gothe, Nicholas Esker, Kenneth E. Gregorich, M. Albers, T. Lauritsen, S. Zhu, D. Seweryniak, Y. Qiu, R. M. Clark, Joonas Konki, C. J. Chiara, B. B. Back, B. Baartman, Martín Alcorta, Jun Chen, Panu Ruotsalainen, M. P. Carpenter, John P. Greene, I. Ahmad, Paul Greenlees, Calem Hoffman, C. M. Campbell, P. F. Bertone, L. A. Bernstein, Guy Savard, D. J. Hartley, R. V. F. Janssens, Sanna Stolze, J. T. Kwarsick, A. Wiens, A. M. Rogers, J. M. Gates, F. G. Kondev, M. Cromaz, T. L. Khoo, J. Rissanen, D. T. Doherty, S. S. Hota, and H. M. David
- Subjects
Physics ,010308 nuclear & particles physics ,Fission ,General Physics and Astronomy ,Orders of magnitude (numbers) ,01 natural sciences ,Nuclear physics ,Crystallography ,0103 physical sciences ,Quasiparticle ,010306 general physics ,Ground state ,Spontaneous fission ,Digital data acquisition system - Abstract
Two isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and 247(73) μs have been discovered in the heavy ^{254}Rf nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the K^{π}=8^{-}, ν^{2}(7/2^{+}[624],9/2^{-}[734]) two-quasineutron and the K^{π}=16^{+}, 8^{-}ν^{2}(7/2^{+}[624],9/2^{-}[734])⊗8^{-}π^{2}(7/2^{-}[514],9/2^{+}[624]) four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter N=150 isotones. The four-quasiparticle isomer is longer lived than the ^{254}Rf ground state that decays exclusively by spontaneous fission with a half-life of 23.2(1.1) μs. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state.
- Published
- 2015
29. Persistence of collective behavior at high spin in theN=88nucleusTb153
- Author
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J. Simpson, E. S. Paul, M. A. Riley, T. Lauritsen, P. J. Nolan, D. C. Radford, J. P. Revill, J. Ollier, P. Hampson, J. M. Rees, R. V. F. Janssens, F. G. Kondev, U. Garg, Marina Petri, S. Zhu, Saul L. Miller, A. D. Ayangeakaa, Martin Carpenter, P. J. R. Mason, Ingemar Ragnarsson, J. T. Matta, D. J. Hartley, C. J. Chiara, Xuejun Wang, Calem Hoffman, and L. L. Riedinger
- Subjects
Physics ,Nuclear and High Energy Physics ,Collective behavior ,medicine.anatomical_structure ,Spins ,Excited state ,Yrast ,medicine ,Gammasphere ,Atomic physics ,Nucleus ,Line (formation) ,Spin-½ - Abstract
Excited states in the N = 88 nucleus Tb-153 were observed up to spin similar to 40 in an experiment utilizing the Gammasphere array. The Tb-153 states were populated in a weak alpha 4n evaporation channel of the Cl-37 + Sn-124 reaction. Two previously known sequences were extended to higher spins, and a new decoupled structure was identified. The pi h(11/2) band was observed in the spin region where other N = 88 isotopes exhibit effects of prolate to oblate shape changes leading to band termination along the yrast line, whereas Tb-153 displays a persistent collective behavior. However, minor perturbations of the very highest state in both signatures of this h(11/2) band are observed, which perhaps signal the start of the transition towards band termination. (Less)
- Published
- 2015
30. High-spin terminating states in theN=88Ho155andEr156isotones
- Author
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R. V. F. Janssens, D. C. Radford, J. Ollier, J. P. Revill, D. J. Hartley, P. J. R. Mason, J. Simpson, J. T. Matta, C. J. Chiara, T. Lauritsen, Martin Carpenter, F. G. Kondev, Ingemar Ragnarsson, A. D. Ayangeakaa, E. S. Paul, P. J. Nolan, Xuejun Wang, P. Hampson, Saul L. Miller, S. Zhu, Jnaneswari Gellanki, J. M. Rees, Calem Hoffman, U. Garg, Marina Petri, and M. A. Riley
- Subjects
Physics ,Nuclear and High Energy Physics ,Normalization property ,medicine.anatomical_structure ,medicine ,Shell (structure) ,Atomic physics ,Spin (physics) ,Nucleus ,Excitation - Abstract
The Sn-124(Cl-37, 6n gamma) fusion-evaporation reaction at a bombarding energy of 180 MeV has been used to significantly extend the excitation level scheme of Ho-155(67)88. The collective rotational behavior of this nucleus breaks down above spin I similar to 30 and a fully aligned noncollective (band terminating) state has been identified at I-pi = 79/2(-). Comparison with cranked Nilsson-Strutinsky calculations also provides evidence for core-excited noncollective states at I-pi = 87/2(-) and (89/2(+)) involving particle-hole excitations across the Z = 64 shell gap. A similar core-excited state in Er-156(68)88 at I-pi = (46(+)) is also presented.
- Published
- 2015
31. Observation ofγvibrations and alignments built on non-ground-state configurations inDy156
- Author
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D. Curien, N. Cooper, C. W. Beausang, David Miller, W. D. Kulp, S. Zhu, E. A. McCutchan, J. L. Wood, C.-H. Yu, F. G. Kondev, N. Redon, P. E. Garrett, J. M. Allmond, C. J. Chiara, R. V. F. Janssens, V. Werner, Judy M. Simpson, M. A. Riley, Xuan Wang, I. Stefanescu, D. J. Hartley, S. N. T. Majola, B. J. P. Gall, J. Piot, M. P. Carpenter, L. L. Riedinger, T. Lauritsen, and J.F. Sharpey-Schafer
- Subjects
Physics ,Nuclear and High Energy Physics ,Spins ,Yrast ,Pairing ,Nuclear Theory ,Gammasphere ,S band ,Atomic physics ,Nuclear Experiment ,Nucleon ,Spin (physics) ,Ground state - Abstract
The exact nature of the lowest Kπ=2+ rotational bands in all deformed nuclei remains obscure. Traditionally they are assumed to be collective vibrations of the nuclear shape in the γ degree of freedom perpendicular to the nuclear symmetry axis. Very few such γ bands have been traced past the usual backbending rotational alignments of high-j nucleons. We have investigated the structure of positive-parity bands in the N=90 nucleus Dy156, using the Nd148(C12,4n)Dy156 reaction at 65 MeV, observing the resulting γ-ray transitions with the Gammasphere array. The even- and odd-spin members of the Kπ=2+γ band are observed up to 32+ and 31+, respectively. This rotational band faithfully tracks the ground-state configuration to the highest spins. The members of a possible γ vibration built on the aligned yrast S band are observed up to spins 28+ and 27+. An even-spin positive-parity band, observed up to spin 24+, is a candidate for an aligned S band built on the seniority-zero configuration of the 0+2 state at 676 keV. The crossing of this band with the 0+2 band is at ℏωc=0.28(1)MeV and is consistent with the configuration of the 0+2 band not producing any blocking of the monopole pairing.
- Published
- 2015
32. Transverse Wobbling inPr135
- Author
-
S. Zhu, Supratik Mukhopadhyay, P. V. Madhusudhana Rao, S. S. Ghugre, D. Vijaya Lakshmi, T. Lauritsen, R. Palit, R. V. F. Janssens, F. G. Kondev, S. Saha, S. Ray, C. M. Petrache, A. K. Sinha, T. Trivedi, D. Seweryniak, R. Raut, A. D. Ayangeakaa, D. J. Hartley, J. T. Matta, D. Patel, K. W. Schlax, S. K. Tandel, M. Kumar Raju, F. Dönau, C. J. Chiara, U. Garg, Wei Li, M. P. Carpenter, S. Frauendorf, and J. Sethi
- Subjects
Physics ,Quantitative Biology::Biomolecules ,Rotor (electric) ,Nuclear Theory ,General Physics and Astronomy ,Physics::Geophysics ,law.invention ,Transverse plane ,medicine.anatomical_structure ,law ,Physics::Space Physics ,Quasiparticle ,medicine ,Astrophysics::Earth and Planetary Astrophysics ,Atomic physics ,Magnetic dipole ,Nuclear theory ,Nucleus - Abstract
A pair of transverse wobbling bands is observed in the nucleus ^{135}Pr. The wobbling is characterized by ΔI=1, E2 transitions between the bands, and a decrease in the wobbling energy confirms its transverse nature. Additionally, a transition from transverse wobbling to a three-quasiparticle band comprised of strong magnetic dipole transitions is observed. These observations conform well to results from calculations with the tilted axis cranking model and the quasiparticle rotor model.
- Published
- 2015
33. Observation of states beyond band termination in156, 157, 158Er and strongly deformed structures in173, 174, 175Hf
- Author
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G. Mukherjee, R. A. Kaye, M. Danchev, P. Chowdhury, P. J. Nolan, R. M. Clark, J. Goon, T. Lauritsen, F. G. Kondev, P. T. W. Choy, M. A. Riley, Jing-ye Zhang, E. F. Moore, P. Fallon, D. B. Campbell, A. Pipidis, D. T. Joss, E. S. Paul, E. Ngijoi-Yogo, Martin Carpenter, B. McClain, Andreas Görgen, R. W. Laird, A. Aguilar, Daniel Ward, D. J. Hartley, Karin Lagergren, R. V. F. Janssens, Philip M Walker, G.D. Dracoulis, A. O. Evans, D. E. Appelbe, C. R. Bingham, M. K. Djongolov, Fikret Saric, G. Sletten, G. B. Hagemann, L. L. Riedinger, M. Cromaz, H. I. Park, T. L. Khoo, Ingemar Ragnarsson, D. M. Cullen, S. K. Tandel, A. O. Macchiavelli, and J. Simpson
- Subjects
Physics ,Angular momentum ,Particle properties ,Deformation (mechanics) ,Spectrometer ,chemistry.chemical_element ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Erbium ,Superdeformation ,chemistry ,Gammasphere ,Atomic physics ,Spin (physics) ,Mathematical Physics - Abstract
High-spin terminating bands in heavy nuclei were first identified in nuclei around Er-158(90). While examples of terminating states have been identified in a number of erbium isotopes, almost nothing is known about the states lying beyond band termination. In the present work, the high-spin structure of Er-156,Er-157,Er-158 has been studied using the Gammasphere spectrometer. The subject of triaxial superdeformation and 'wobbling' modes in Lu nuclei has rightly attracted a great deal of attention. Very recently four strongly or superdeformed (SD) sequences have been observed in Hf-174, and cranking calculations using the Ultimate Cranker code predict that such structures may have significant triaxial deformation. We have performed two experiments in an attempt to verify the possible triaxial nature of these bands. A lifetime measurement was performed to confirm the large (and similar) deformation of the bands. In addition, a high-statistics, thin-target experiment took place to search for linking transitions between the SD bands, possible wobbling modes, and new SD band structures.
- Published
- 2006
34. Multiple excitation modes inHf163
- Author
-
T. Lauritsen, M. P. Carpenter, Q. A. Ijaz, S. Mukhopadhyay, C. R. Hoffman, S. Zhu, R. B. Yadav, G. Gürdal, L. L. Riedinger, J. C. Marsh, F. G. Kondev, R. V. F. Janssens, G.B. Hagemann, D. J. Hartley, and W. C. Ma
- Subjects
Physics ,Nuclear and High Energy Physics ,Atomic physics ,Excitation - Published
- 2014
35. Beyond band termination in157Er and the search for wobbling excitations in strongly deformed174Hf
- Author
-
G.D. Dracoulis, A. Pipidis, D. T. Joss, J. Y. Zhang, H. I. Park, F. G. Kondev, E. S. Paul, Ingemar Ragnarsson, A. Aguilar, R. W. Laird, P. J. Nolan, E. Ngijoi-Yogo, R. M. Clark, C. R. Bingham, Fikret Saric, Karin Lagergren, Daniel Ward, D. J. Hartley, J. Goon, R. V. F. Janssens, G. Sletten, D. M. Cullen, P. T. W. Choy, M. K. Djongolov, B. McClain, A. O. Evans, S. K. Tandel, J. Simpson, P. M. Walker, D. E. Appelbe, G. Mukherjee, L. L. Riedinger, R. A. Kaye, P. Chowdhury, M. A. Riley, A. O. Macchiavelli, M. P. Carpenter, M. Danchev, D. B. Campbell, T. Lauritsen, G.B. Hagemann, Andreas Görgen, P. Fallon, E. F. Moore, M. Cromaz, and T. L. Khoo
- Subjects
Superdeformation ,Physics ,Nuclear and High Energy Physics ,Angular momentum ,Gammasphere ,Gamma spectroscopy ,Atomic physics ,Deformation (meteorology) ,Spectroscopy ,Spin (physics) ,Excitation - Abstract
High-spin terminating bands in heavy nuclei were first identified in nuclei around Er-158(90). While examples of special terminating states have been identified in a number of erbium isotopes, almost nothing is known about the states lying beyond band termination. In the present work the high-spin structure of Er-157 has been studied using the Gammasphere spectrometer. The subject of triaxial superdeformation and 'wobbling' modes in Lu nuclei has rightly attracted a great deal of attention. Very recently, four strongly or superdeformed (SD) sequences have been observed in Hf-174 and ultimate cranker calculations predict, such structures may have significant triaxial deformation. We have performed two experiments in an attempt to verify the possible triaxial nature of these bands. A lifetime measurement was performed to confirm the large (and similar) deformation of the bands. In addition, a high-statistics, thin-target experiment was run to search for linking transitions between the SD bands and possible wobbling modes.
- Published
- 2005
36. Quadrupole moment measurements of TSD1 and TSD2 bands in167Lu
- Author
-
Y. C. Zhang, D. J. Hartley, T. L. Khoo, E. F. Moore, Christian Rønn Hansen, C. Engelhardt, H. Amro, G. Gürdal, B. Herskind, H. Hübel, C. W. Beausang, M. P. Carpenter, P. Bringel, T. Lauritsen, G. Sletten, G.B. Hagemann, W. C. Ma, A. Neusser, D. S. Brenner, D. A. Meyer, D.G. Roux, R. B. Yadav, and R. F. Casten
- Subjects
Physics ,Nuclear and High Energy Physics ,symbols.namesake ,Spectrometer ,Phonon ,Attenuation ,Quadrupole ,Gamma ray ,symbols ,Gammasphere ,Atomic physics ,Doppler effect ,Coincidence - Abstract
The triaxial strongly deformed (TSD) bands in 167Lu were populated by the 123Sb(48Ca, 4n) reaction with a beam energy of 203 MeV. Gamma rays, requiring five fold or more in prompt coincidence, were detected with the Gammasphere spectrometer. Of particular interests are TSD bands 1 and 2 which have previously been interpreted as zero phonon and one phonon wobbling bands, respectively. Using the Doppler shift attenuation method (DSAM), a preliminary transition quadrupole moment of 6.9+0.3−0.3 eb was extracted for the TSD1 band. Data analysis continues for TSD2 which is considerably more weakly populated.
- Published
- 2005
37. Coulomb excitation and transfer reactions with neutron-rich radioactive beams
- Author
-
A. Woehr, N. V. Zamfir, J. C. Batchelder, J. K. Hwang, Y. Larochelle, R. L. Varner, C. J. Barton, A. Galindo-Uribarri, J. Gomez del Campo, D. J. Hartley, B. Fuentes, Chang-Hong Yu, M. Danchev, J. F. Liang, W. Krolas, Paul Hausladen, C. Baktash, Dan Shapira, C. R. Bingham, J. R. Beene, D. W. Stracener, M. L. Halbert, A. Piechaczek, Mark A. Caprio, Carl J Gross, D. C. Radford, P. E. Mueller, E. Padilla, and J. Pavan
- Subjects
Physics ,Radioactive ion beams ,Nuclear and High Energy Physics ,Astrophysics::High Energy Astrophysical Phenomena ,Hadron ,Gamma ray ,Coulomb excitation ,Nuclear physics ,Excited state ,Nuclear fusion ,Neutron ,Atomic physics ,Nuclear Experiment ,Beam (structure) - Abstract
Neutron-rich radioactive ion beams available from the HRIBF allow a variety of measurements around the 132Sn region, including Coulomb excitation and single-nucleon transfer. The B(E2;0+ → 2+) values for first 2+ excited states of even-even neutron-rich 132-136Te and 126-130Sn have been measured by Coulomb excitation in inverse kinematics. Neutron transfer onto a 134Te beam from 9Be and 13C targets, to populate single-particle states in 135Te, has also been studied. Gamma rays from the 13C(134Te, 12C) reaction were used to identify the νi13/2 state in 135Te, at an energy of 2109 keV. These and other results, and plans for future experiments with these neutron-rich beams, are presented.
- Published
- 2005
38. Coulomb excitation and transfer reactions with rare neutron-rich isotopes
- Author
-
Carl J Gross, J. Gomez del Campo, R. L. Varner, J. C. Batchelder, M. L. Halbert, Paul Hausladen, M. Danchev, Y. Larochelle, Daniel W Stracener, J. K. Hwang, Chang-Hong Yu, A. Piechaczek, D. C. Radford, A. Galindo-Uribarri, C. J. Barton, C. Baktash, Dan Shapira, Mark A. Caprio, A. Woehr, W. Krolas, N. V. Zamfir, E. Padilla, P. E. Mueller, C. R. Bingham, J. F. Liang, B. Fuentes, J. R. Beene, D. J. Hartley, and J. Pavan
- Subjects
Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Isotope ,Astrophysics::High Energy Astrophysical Phenomena ,Excited state ,Quasiparticle ,Gamma ray ,Neutron ,Coulomb excitation ,Atomic physics ,Random phase approximation ,Beam (structure) - Abstract
Neutron-rich radioactive ion beams available from the HRIBF allow a variety of measurements around the 132Sn region, including Coulomb excitation, fusion-evaporation, and neutron transfer. The B ( E 2 ; 0 + → 2 + ) value for first 2+ excited states of even-even neutron-rich 132–136Te and 126–134Sn have been measured by Coulomb excitation in inverse kinematics. The results are discussed in terms of the shell model and the quasiparticle random phase approximation. Neutron transfer onto a 134Te beam, from 9Be and 13C targets to populate single-particle states in 135Te, has also been studied. Gamma rays from the 13C(134Te, 12C) reaction were used to identify the ν i 13 / 2 state in 135Te, at an energy of 2109 keV. These and other results, and plans for future experiments with these neutron-rich beams, are presented.
- Published
- 2005
39. Wobbling excitations in strongly deformed Hf nuclei?
- Author
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G. Sletten, Gaurab Mukherjee, M. Cromaz, T. L. Khoo, F. G. Kondev, E. F. Moore, A. Aguilar, P. Chowdhury, G.B. Hagemann, R. V. F. Janssens, T. Lauritsen, R. W. Laird, M. K. Djongolov, M. Danchev, B. McClain, R. A. Kaye, D. J. Hartley, J. Goon, H. I. Park, George Dracoulis, L. L. Riedinger, P. Fallon, E. Ngijoi-Yogo, M. P. Carpenter, D. B. Campbell, M. A. Riley, A. O. Macchiavelli, P. M. Walker, D. M. Cullen, S. K. Tandel, C. R. Bingham, and J. Y. Zhang
- Subjects
Physics ,Nuclear and High Energy Physics ,Isotope ,Phonon ,Nutation ,Attenuation ,Quadrupole ,Gammasphere ,Deformation (engineering) ,Atomic physics ,Excitation - Abstract
Two Gammasphere experiments have been performed in order to establish the possible triaxial nature of strongly deformed (SD) bands in 174Hf. A lifetime measurement, using the Doppler-shift attenuation method, confirmed the large deformation of the four previously observed bands in this nucleus with transition quadrupole moments ranging from 12.6 to 13.8 b. These values are significantly larger than those predicted for triaxial minima by ultimate cranker (UC) calculations. A thin-target, high-statistics experiment was also carried out to search for linking transitions between the SD bands. No such transitions, which represent an experimental signature for wobbling modes, were observed. Four additional SD bands were found in 174Hf together with a single SD band in 173Hf. These results indicate that the strongly deformed sequences of N ≈ 102 Hf isotopes behave differently than the triaxial strongly deformed (TSD) bands found in Lu nuclei near N = 92 . The interpretation of these bands in terms of possible stable triaxial deformation is confronted with the experimental findings and UC predictions.
- Published
- 2005
40. Nuclear structure studies with heavy neutron-rich RIBS at the HRIBF
- Author
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C. Baktash, Dan Shapira, J. Mas, P. E. Mueller, B. Fuentes, Chang-Hong Yu, A. Galindo-Uribarri, Carl J Gross, N. V. Zamfir, C. J. Barton, D. J. Hartley, J. Gomez del Campo, T. A. Lewis, Daniel W Stracener, M. L. Halbert, J. R. Beene, E. Padilla, Mark A. Caprio, J. F. Liang, R. L. Varner, Y. Larochelle, and D. C. Radford
- Subjects
Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Excited state ,SHELL model ,Nuclear structure ,Quasiparticle ,Neutron ,Coulomb excitation ,Atomic physics ,Random phase approximation ,Beam (structure) - Abstract
Neutron-rich radioactive ion beams available from the HRIBF allow a variety of exciting measurements around the 132 Sn region, including Coulomb excitation, fusion-evaporation, and neutron transfer. The B ( E 2 ; 0 + → 2 + ) value for first 2 + excited states of neutron-rich 132,134,136 Te and 126,128,130,132,134 Sn have been measured by Coulomb excitation in inverse kinematics. The results are discussed in terms of the shell model and the quasiparticle random phase approximation. Neutron transfer onto a 134 Te beam, from 9 Be and 13 C targets to populate single-particle states in 135 Te, has also been studied. Results, and plans for future experiments with these neutron-rich beams, are presented.
- Published
- 2004
41. The CARDS array for neutron-rich decay spectroscopy at HRIBF
- Author
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D. Fong, W. Krolas, K. P. Rykaczewski, E. H. Spejewski, A. V. Ramayya, J. A. Winger, J. D. Cole, J. H. Hamilton, A. Piechaczek, Mohammed N. Tantawy, J. L. Wood, Robert Grzywacz, D. W. Stracener, D. Kulp, D. J. Hartley, P. E. Garrett, H.K. Carter, J. C. Batchelder, Y. Larochelle, Jean-Christophe Bilheux, C. R. Bingham, J. K. Hwang, and E. F. Zganjar
- Subjects
Physics ,Nuclear and High Energy Physics ,Electron spectrometer ,Ion beam ,Physics::Instrumentation and Detectors ,Preamplifier ,Scintillator ,Particle detector ,Semiconductor detector ,Nuclear physics ,Physics::Accelerator Physics ,High Energy Physics::Experiment ,Neutron ,Nuclear Experiment ,Instrumentation ,Radioactive decay - Abstract
An array for decay studies of neutron-rich nuclei has been commissioned for use at the UNISOR separator at Holifield Radioactive Ion Beam Facility. This array consists of three segmented clover Ge detectors, plastic scintillators, and a high-resolution (∼1 keV) Si conversion electron spectrometer. These detectors are mounted on a support that surrounds a moving tape collector. This system has been named clover array for radioactive decay studies. The detectors have been outfitted with digital flash ADCs (XIA DGFs) that fit the preamp signals, with built-in pileup rejection.
- Published
- 2003
42. Limits of the energy-spin phase space beyond the proton drip line: entry distributions of Pt and Au isobars
- Author
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K. Abu Saleem, W. C. Ma, D. J. Hartley, F. G. Kondev, C. J. Lister, C. N. Davids, W. Reviol, L. L. Riedinger, R. V. F. Janssens, Jolie Cizewski, M. B. Smith, I. Wiedenhöver, I. Ahmad, M. P. Carpenter, G. L. Poli, M. Danchev, T. L. Khoo, D. Seweryniak, J. J. Ressler, A. M. Heinz, T. Lauritsen, and H. Amro
- Subjects
Physics ,Nuclear and High Energy Physics ,Angular momentum ,Proton ,Nuclear Theory ,Hadron ,Baryon ,Nuclear physics ,Phase space ,Isobar ,Atomic physics ,Nuclear Experiment ,Nucleon ,Spin-½ - Abstract
Entry distributions in angular momentum and excitation energy have been measured for several very proton-rich isotopes of Pt and Au. This is the first systematic study of the energy-spin phase space for nuclei near and beyond the proton drip line. Comparisons are made between the distributions associated with proton-unbound Au nuclei and more stable Pt isobars. In 173 Au the first evidence is seen for the limits of excitation energy and angular momentum which a nucleus beyond the proton drip line can sustain.
- Published
- 2003
43. Characterization of octupole-type structures inTh221
- Author
-
O. L. Pechenaya, S. Zhu, D. G. Sarantites, R. V. F. Janssens, K. Hauschild, X. Chen, J. Snyder, D. Seweryniak, C. J. Chiara, A. Lopez-Martens, M. Montero, D. J. Hartley, M. P. Carpenter, S. Frauendorf, W. Reviol, and T. Lauritsen
- Subjects
Physics ,Nuclear and High Energy Physics ,Yrast ,Parity (physics) ,Gammasphere ,Detector array ,Atomic physics ,Characterization (mathematics) ,Type (model theory) ,Nuclear Experiment ,Spin (physics) - Abstract
A detailed level scheme for $^{221}\mathrm{Th}$ has been established in an experiment using the $^{18}\mathrm{O}+{}^{207}\mathrm{Pb}$ reaction at 96 MeV. The evaporation residues from this fissile system were selected with the HERCULES detector array and residue-gated $\ensuremath{\gamma}$ rays were measured with Gammasphere. Three band structures of interlinked, alternating-parity levels are observed, two of which are non-yrast. In addition, several high-lying excitations are found. The yrast band is seen up to spin-parity $37/{2}^{\ensuremath{-}}$ and $39/{2}^{+}$, beyond which a high-spin feeding transition is observed. The non-yrast sequences are interpreted as parity-doublet structures, based on a configuration similar to that of the yrast band in $^{223}\mathrm{Th}$ $(K=5/2)$. The key properties of even-odd nuclei in this mass region $[B(E1)/B(E2)$ and $B(M1)/B(E2)$ ratios, spin alignments, parity splittings] are reviewed.
- Published
- 2014
44. High-spin structure of odd-oddRe172
- Author
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M. A. Riley, E. E. Pedicini, D. J. Hartley, R. V. F. Janssens, S. Zhu, Xuan Wang, P. Chowdhury, J. Simpson, U. Garg, J. Cavey, T. Lauritsen, W. C. Ma, F. G. Kondev, J. R. Vanhoy, L. L. Riedinger, J. T. Matta, E.G. Jackson, E. S. Paul, A. D. Ayangeakaa, S. L. Miller, S. S. Hota, J. J. Carroll, C. J. Chiara, M. P. Carpenter, and Marc Litz
- Subjects
Physics ,Nuclear and High Energy Physics ,medicine.anatomical_structure ,Spectrometer ,medicine ,Gammasphere ,Spin structure ,Atomic physics ,Nuclear Experiment ,Nucleus ,Spin-½ - Abstract
A significant extension of the level scheme for the odd-odd nucleus $^{172}\mathrm{Re}$ was accomplished through the use of the Gammasphere spectrometer. States up to a tentative spin assignment of 39 were observed and two new structures were identified. Configuration assignments are proposed based on alignment properties and observed band crossings.
- Published
- 2014
45. Study of 169Hf at high rotational frequency
- Author
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M. Bergström, S. W. Ødegård, A. Maj, A. Bracco, L. L. Riedinger, R. Terry, H. Hübel, W. C. Ma, S. Frattini, B. Herskind, K. A. Schmidt, C. J. Lister, T. Lauritsen, J. Domscheit, P. G. Varmette, M. P. Carpenter, G. Sletten, S. Siem, Benedicte Million, T. L. Khoo, R. V. F. Janssens, G.B. Hagemann, I. Wiedenhöver, and D. J. Hartley
- Subjects
Physics ,Nuclear and High Energy Physics ,Excited state ,Quasiparticle ,Degrees of freedom (physics and chemistry) ,Nuclear fusion ,Atomic physics ,Nucleon ,Excitation ,Spectral line ,Spin-½ - Abstract
High-spin properties of the nucleus 169Hf have been studied through the fusion evaporation reaction 96Zr(76Ge,3n)169Hf at a beam energy of 310 MeV. The known rotational bands have been extended considerably and 6 new bands have been established, four of which form coupled bands with pronounced M1 connections. Quasiparticle assignments are suggested for the new band structures, and it appears that coupling to vibrational degrees of freedom plays a role. Both coupled bands involve the excitation of quasiprotons. In the region of highest spin, a large alignment gain is interpreted in terms of a mixed crossing where an h 9/2 and an h 11/2 quasiproton provide the two signatures of the aligning configuration.
- Published
- 2001
46. Identification of excited structures in proton unbound nuclei 173,175,177Au: shape co-existence and intruder bands
- Author
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Jolie Cizewski, K. Abu Saleem, F. G. Kondev, G. L. Poli, R. V. F. Janssens, J. J. Ressler, C. J. Lister, W. C. Ma, T. Lauritsen, M. P. Carpenter, D. J. Hartley, I. Ahmad, I. Wiedenhöver, T. L. Khoo, D. Seweryniak, C. N. Davids, M. Danchev, W. Reviol, L. L. Riedinger, H. Amro, M. B. Smith, and A. M. Heinz
- Subjects
Physics ,Nuclear and High Energy Physics ,Proton ,Isotope ,Yrast ,Excited state ,Prolate spheroid ,Atomic physics ,Deformation (engineering) ,Line (formation) - Abstract
Excited states in the proton-unbound 173,175,177 Au nuclei were identified for the first time. Level structures associated with three different shapes were observed in 175 Au. While the yrast lines of 175 Au and 177 Au consist of a prolate band built upon the intruder 1/2 + [660] ( i 13/2 ) proton orbital, no sign of collectivity was observed in the lighter 173 Au isotope. Implications for the deformation associated with these structures are discussed with a focus on shape co-existence in the vicinity of the proton-drip line.
- Published
- 2001
47. First evidence for triaxial superdeformation in 168Hf
- Author
-
A. Bracco, G. Sletten, H. Amro, H. Hübel, T. Lauritsen, P.G. Varmette, I. Wiedenhöver, R. B. Piercey, S. Siem, S. Frattini, K. A. Schmidt, C. J. Lister, W. C. Ma, D. J. Hartley, J. N. Wilson, M. P. Carpenter, L. L. Riedinger, M. Bergström, B. Herskind, J. Domscheit, F. G. Kondev, Benedicte Million, T. L. Khoo, S. W. Ødegård, J. A. Winger, Gro Hagemann, and R. V. F. Janssens
- Subjects
Superdeformation ,Physics ,Maxima and minima ,Nuclear and High Energy Physics ,Proton ,Deformation (mechanics) ,Quadrupole ,Atomic physics - Abstract
Three superdeformed (SD) bands have been found in 168Hf. Lifetime measurements revealed a large quadrupole moment, Q t ∼11.4 e b , for the strongest band (TSD1). Theoretical calculations using the Ultimate Cranker code predict high-spin SD minima (ϵ2∼0.43) with stable triaxial deformations of γ∼+20° and γ∼−15°. The measured Qt value suggests that band TSD1 corresponds, most likely, to a deformation with a positive γ value. This constitutes the first evidence for triaxial superdeformation in an even proton system.
- Published
- 2001
48. Chiral Doublet Structures in Odd-OddN=75Isotones: Chiral Vibrations
- Author
-
Mark A. Caprio, C. W. Beausang, D. R. LaFosse, J. R. Cooper, N. V. Zamfir, D. L. Balabanski, A. A. Hecht, J. R. Novak, D. J. Hartley, D. B. Fossan, R. Krücken, K. Starosta, C. J. Chiara, J. Y. Zhang, S. Frauendorf, V. I. Dimitrov, Takeshi Koike, and K. E. Zyromski
- Subjects
Physics ,Chiral symmetry ,Valence (chemistry) ,Yrast ,General Physics and Astronomy ,Atomic physics ,Chiral symmetry breaking - Abstract
New sideband partners of the yrast bands built on the $\ensuremath{\pi}{h}_{11/2}\ensuremath{\nu}{h}_{11/2}$ configuration were identified in ${}_{55}\mathrm{Cs}$, ${}_{57}\mathrm{La}$, and ${}_{61}\mathrm{Pm}$ $N\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}75$ isotones of ${}^{134}\mathrm{Pr}$. These bands form with ${}^{134}\mathrm{Pr}$ unique doublet-band systematics suggesting a common basis. Aplanar solutions of 3D tilted axis cranking calculations for triaxial shapes define left- and right-handed chiral systems out of the three angular momenta provided by the valence particles and the core rotation, which leads to spontaneous chiral symmetry breaking and the doublet bands. Small energy differences between the doublet bands suggest collective chiral vibrations.
- Published
- 2001
49. Systematic study of energy-spin entry distributions at the proton dripline in the A∼170 region
- Author
-
F. G. Kondev, J. J. Ressler, C. J. Lister, Jolie Cizewski, Andreas Martin Heinz, R. V. F. Janssens, I. Wiedenhöver, T. Lauritsen, K. Abu Saleem, H. Amro, T. L. Khoo, C. N. Davids, M. Danchev, D. Seweryniak, W. Reviol, L. L. Riedinger, M. B. Smith, Iftikhar Ahmad, M. P. Carpenter, Gian Luca Poli, D. J. Hartley, and W. C. Ma
- Subjects
Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Proton ,Energy (signal processing) ,Spin-½ - Published
- 2001
50. First observation of excited structures in neutron deficient, odd-mass Pt, Au and Hg nuclei
- Author
-
M. Danchev, A. M. Heinz, T. L. Khoo, R. V. F. Janssens, H. Amro, D. J. Hartley, Jolie Cizewski, C. J. Lister, K. Abu Saleem, B. Herskind, F. G. Kondev, C. N. Davids, J. J. Ressler, R. A. Kaye, M. P. Carpenter, I. Ahmad, A. A. Sonzogni, W. C. Ma, J. Caggiano, T. Lauritsen, D. Seweryniak, Sunniva Siem, W. Reviol, Gian Luca Poli, P. G. Varmette, L. L. Riedinger, I. Wiedenhöver, Martín Alcorta, and M. B. Smith
- Subjects
Nuclear physics ,Nuclear reaction ,Physics ,Nuclear and High Energy Physics ,Excited state ,Nuclear structure ,Neutron ,Atomic physics - Published
- 2001
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